Natural-gas conductor



(No Model.)

J. N. PBW.

NATURAL GAS CONDUCTOR No. 321,637. Patented Juy 7, 1885.

And.

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ihvrrno Srnrns Parenti @reina JOSEPH N. PEW, OF PITTSBRG, PENNSYLVANIA,

NATURAL-GAS CONDUCTOR.

SPECIFICATION forming part of Letters Patent No. 321,637, dated July 7,1885.

Application flcd February Q4, 1885.

fo @ZZ whom, t muy concern:

Be it known that I, Josnrn N. Paw, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovement in NaturalGas Conductors; and I do hereby declare thefollowing to be a full, clear, and exact description thereof.

Serious difficulty has been experienced in the conduction anddistribution of natural gas, owing to the low temperature and highpressure at which it cornes from the wells. The temperature is about 42Fahrenheit, and the pressure in the neighborhood ol' two hundred poundsto the square inch. The effect of the low temperature is to contract thepipes, and where they are exposed to the temperature of the atmosphere,it' the latter be higher, an expansion will tal-:e place, so that thereis a constant expansion and contraction going on in the pipes, whichtend to loosen the joints and cause them to leak. 'This leakage, owingto the highly'explosive and extremely dangerous nature ofthe gas, is avery serious detri As the escape of the gas hasl been the cause of manyserious explosions involving destruction of property and loss ot' life,attempts have been made to obviate the con traction and expansion of thepipes by burying them deep enough inthe ground to be below the effect ofthe changes of temperature at the surface, the theory being that thepipes would then remain at the temperature of the gas at all times; butI have discovered that changes in the temperature are caused hy thereduction of pressure in the pipes, owing to the greater or less demandsupon them by the users of the gas, and that to maintain them at auniform temperature it isnecessary that the pressure also remainsuniform. This is impossible, owing to the fac-t that during the day-timethere is usually a much greater demand than during the night. and as thepipes are drawn on and the gas therein is more or less exhausted andreduced in pressure its eX- pansion therein produces a reduction ofternperature, which causes a constant expansion and contraction of thepipes, however deep they may he buried. It has been customary to laythese pipes through the streets below (No model the. water and gas mainsand service-pipes, so that leakage therefrom in ascending through theground encounters the water and-gas service-pi pes which lead into thecellars and basements of buildings. There is always more or less spacearound a scrvicepipe, and the gas encountering` them will follow` suchpipes, passing along these spaces, and enters the cellars and basementsol` buildings and collects there, and in many cases explodes withdisastrous results. f

Various provisions have been made for the purpose of carrying oiftheleakage from natural-gas mains, and stand-pipes leading up from a boxor a layer of gravel or broken stone surrounding each joint anddischarging the same in the open air have been used. These things,however, have not proven to be entirely eflioaeious, as more or lessleakage will seek the channels before mentioned around the servicepipesand enter adjacent buildings. Where the gas-pipes are situate above thesurface of the ground 1n uch of the danger of explosion is averted; butthis is impracticable in the streets of towns and cities.

rIhe object of my improvementisto increase the safety of the conductionand distribution of natural gas, and, broadly stated, it consists inlaying the pipes in a suitable trench at the surface of the ground, andabove the water, illumi netting-gas, and other distributing pipes, whichtrench is covered throughout its entire length by a ventilating-capprovided with slots or holes for permitting the escape of the leakagegas into the open air, where., having no opportunity to collect, it ispractically harmless. I prefer to provide my mains and pipes withexpansion-joints,which will permit of the expansion and contraction ofthe pipes without danger of disrupting any part and causing -a leak.

To enable others skilled in the art to make and use my invention, I willnow describe it by reference to the accompanying drawings, in which-Figure l is a longitudinal section of the trench, showing the pipe andthe means of supporting the saine therein. Fig. 2 is av cross-section onthe line .r x of Fig. 1.

Like letters of reference indicate like parts.

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I form a shallow trench, a, in the bottom of which, at suitableintervals-say about eight feet apart-I lay erossti1nbers I), of hardwood, such as oak or other suitable material. The sides of the trenchare lined with timbers c, which preferably break Y joint with eachother, so as to make a stronger structure, and on top of said timbersare cross-timbers d. The timbers b and d and the intermediate sidetimbers, c, are'fastened together by vertical bolts e. On top of orbetween the timbers d, I lay a suitable flooring of boards or ironcasings,f, which may be on a'level with the surface of the street orslightly below the same, so as to permit the top to be paved over likethe rest of the street. In the top f is a conti mious line of holesorventopenings, g,which are designed to permit the escape of theleakagegas from the trench. In case the top is paved over provision should bemade forleaving these openings free, which may be done by making themthrough a raised rib or a se ries of short tubes, f/,which will eomeupflush with the surface of the pavement. In ordinary weather there willbe no difficulty in keeping the openings g clear, and-if in the winterthey should become clogged with ice, snow, or dirt, they can be openedby the insertion of a pick or other pointed instrument. The trench a canbe drained of water at suitable intervals by pipes or conduits leadingto the proper place of discharge, and, if desired, steam or heated airmay be blown through the trench by any known or suitable arrangement forthat purpose, not necessary here to be described. The gaspipes h arelaid in the trench, being supported in proper alignment by supports b onthe cross-timbers I), and the sides are of sufficient height to bringthe upper cross-timbers, d, above the top of thepipes. As stated, Iprefer to provide the pipe 7i with expansionjoints.

I do not limit myself or claim the construction of any particular formof expansion-joint in this case, but design to use any of the knownforms suitable to the purpose, one of which is shown at t' in Fig. l.

Vhile I have described and hereinafter claim a preferred form for theconstruction of the pipe-easing inside of the trench, I do not limitmyself to such construction in the use of the features forming the'subject-1n atter of other claims.

My improvement provides for the safe and perfect carrying off of theleakage gas and affords an easy access to the pipes for repairs. Itgives a cheap and efficient manner of laying the pipes, and obviates alldanger of interfering with or injuring the mains and service pipes ofother systems of distribution which may be laid in the streets.

As has been shown, it is impossible to prevent the expansion andcontraction of the pipes, and I therefore prefer to adopt such means aswill obviate danger to thejoints from this cause.

Owing to the conduit being at or near the surface, and yet protected bybeing situate below the level ofthe street, interference with travel anddanger of breakage is averted, and at the same time, owing to thecontinuous vents, the gas is not allowed to accumulate in a confinedspace, so as to lead to the danger of expiosions.

I am aware that an outer casing situate around the gas-main and havingat intervals Ventilating-pipes is not new. I am also aware that suchcasings formed of wood have been employed in connection withtelegraph-wires, and I do not desire to claim, broadly, any of thesefeatures, as the important features of my invention are a conduit forgas-pipes, said conduit having continuous vents and situate at but belowthe level of the surface of the ground, so as to enable the escaping gasto have free access to the open air, and thereby obviate the danger ofthe gas collecting and passing through an inclosed space. These ventsshould be within a short distance of each other, evenlydistributed throughout thelength of the casing, and so numerous that one or more shallbe located within a few inches of the point in the case nearest eachpipe-joint, so that no opportunity shall be aorded for the collection ofescaping gas.

What I claim as myinvention, and desire to secure by Letters Iatent, is-

l. An improvement in the art of conducting and distributing natural gas,which consists in a gas pipe or main placed in a case or trench at orimmediately below the surface, which trench is vented continuouslythroughout its length, substantially as and for the purposes described.

2. A natural-gas pipe, case, or trench at or immediately below thesurface,having its sides lined with strong timbers connected by top andbottom cross-timbers and provided with a continuously-ventedsurface-cover, in combination with a gas-pipe,substantially as and forthe purposes described.

In testimony whereof I have hereunto set my hand this 10th day ofFebruary, A. D. 1885.

Josnrrr N. ruw.

Vitnesses:

W'. BCORWIN, THOMAS B. KERR.

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